The legalization of abortion in the United States in the early 1970s represents one of the most important changes in American social policy in the 20th century. In the span of a decade, abortion went from being illegal nationwide except in rare instances to being legal upon request, with over one quarter of all pregnancies ending in abortion. Previous research indicates that the introduction of legalized abortion led to an immediate decline in birth rates and some evidence indicates it also altered cohort characteristics among those born, at least while they are young. But a full understanding of the outcome of this important social experiment requires additional examination of its impact on cohorts throughout the life course and the mechanism behind such impacts. Specifically, we will address two questions: (1) How do cohorts of children born where abortion is legal differ from those born where abortion is illegal? The outcomes of cohorts born after legalization may differ either because there are fewer "unintended" children born, or because families are smaller, increasing resources available to each child. Previous analysis suggests that there were important impacts of legalization on the characteristics of birth cohorts when young, but there has been little follow up to assess the critical long run implications for cohort quality. We will directly examine the impact of legalization on cohort outcomes such as educational attainment, labor market success, family structure, and incarceration to measure the overall impact on cohort outcomes. (2) What can the legalization of abortion teach us about quantity/quality trade-offs in family size and about the long run impacts of "intendedness?" Not only can we assess the "reduced form" impact of legalization on child outcomes, we can also use the nature of this quasi-experiment to convincingly address the mechanism behind any impact on cohort characteristics. We will estimate directly each of the two channels through which legalization could affect cohort outcomes, providing new and convincing evidence on the critical questions of how family size and intendedness affects outcomes. We will use newly available data from the 2000 Census along with previous Censuses to address these questions. As in our past work, this analysis relies extensively on the natural experiment generated by the early legalization of abortion in a handful of states in 1970 along with the subsequent legalization of abortion in 1973 following the United States Supreme Court decision in Roe v. Wade.